Electronic device

ABSTRACT

An electronic device is provided. The electronic device includes: a substrate, a first light-emitting element, and a second light-emitting element. The first light-emitting element is disposed on the substrate and configured to emit a first color light under a first current density when the substrate provides a first current to the first light-emitting element. The second light-emitting element is disposed on the substrate and configured to emit a second color light under a second current density when the substrate provides a second current to the second light-emitting element. The first current is equal to the second current, and the first current density is different from the second current density.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/823,052 filed on Mar. 25, 2019, and claims priority of China PatentApplication No. 201911110966.X, filed Nov. 14, 2019, the entirety ofwhich is incorporated by reference herein.

BACKGROUND Field of the Invention

The present invention relates to an electronic device, and in particularto an electronic device having ohmic contact electrodes with differentsizes.

Description of the Related Art

Currently, light-emitting diode (LED) chips with different sizes ordifferent driving currents are usually used to achieve white colorbalance. However, the process of manufacturing or activating LEDs may becomplicated by the above arrangement. Therefore, how to solve theaforementioned problem has become an important topic.

BRIEF SUMMARY

Some embodiments of the disclosure provide an electronic device,including: a substrate, a first light-emitting element and a secondlight-emitting element. The first light-emitting element is disposed onthe substrate and configured to emit a first color light under a firstcurrent density when the substrate provides a first current to the firstlight-emitting element. The second light-emitting element is disposed onthe substrate and configured to emit a second color light under a secondcurrent density when the substrate provides a second current to thesecond light-emitting element. The first current is equal to the secondcurrent, and the first current density is different from the secondcurrent density.

Some embodiments of the disclosure provide an electronic device,including: a substrate, a first light-emitting element and a secondlight-emitting element. The first light-emitting element is disposed onthe substrate and configured to emit a first color light, wherein thefirst light-emitting element includes a first semiconductor layer and afirst ohmic contact electrode that is in contact with the firstsemiconductor layer. The second light-emitting element is disposed onthe substrate and configured to emit a second color light, wherein thesecond light-emitting element includes a second semiconductor layer anda second ohmic contact electrode that is in contact with the secondsemiconductor layer. A first ratio of an area of the first ohmic contactelectrode and an area of the first semiconductor layer is different froma second ratio of an area of the second ohmic contact electrode and anarea of the second semiconductor layer.

A detailed description is given in the following embodiments withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be more fully understood by reading thesubsequent detailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 is a cross-sectional view illustrating an electronic device inaccordance with some embodiments of the present disclosure.

FIG. 2 is a top view illustrating the electronic device shown in FIG. 1.

FIG. 3 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 4 is a top view illustrating the electronic device shown in FIG. 3.

FIG. 5 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 6 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 7 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 8 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 9 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 10 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure.

FIG. 11 is a cross-sectional view illustrating a conductive pad inaccordance with some embodiments of the present disclosure.

FIG. 12 is a schematic diagram illustrating the relationship between thelight-emitting efficiency and the current density in accordance withsome other embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The electronic devices of some embodiments of the present disclosure aredescribed in the following description. The specific embodimentsdisclosed are provided merely to clearly describe the usage of thepresent disclosure by some specific methods without limiting the scopeof the present disclosure.

In addition, in this specification, relative expressions may be used.For example, “lower”, “bottom”, “higher” or “top” are used to describethe position of one element relative to another. It should be noted thatif a device is flipped upside down, an element that is “lower” willbecome an element that is “higher”.

It should be understood that, although the terms “first”, “second,”“third” etc. may be used herein to describe various elements, regions,layers and/or portions, and these elements, regions, layers, and/orportions should not be limited by these terms. These terms are only usedto distinguish one element, component, region, layer, or portion. Thus,a first element, component, region, layer or portion discussed belowcould be termed a second element, component, region, layer or portionwithout departing from the teachings of some embodiments of the presentdisclosure. In addition, for the sake of clarity, the terms “first”,“second,” “third” etc. may not be used in the specification todistinguish different elements. The first element, the second elementand/or the third element recited in the claims may be referred to anyelement that conforms to the description in the specification.

Unless defined otherwise, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It shouldbe appreciated that, in each case, the term, which is defined in acommonly used dictionary, should be interpreted as having a meaning thatconforms to the relative skills of the present disclosure and thebackground or the context of the present disclosure, and should not beinterpreted in an idealized or overly formal manner unless so defined inthe present disclosure. In addition, the term “substrate” in thefollowing paragraphs may include elements formed on the substrate orvarious layers covering the substrate, such as any active component(e.g. transistor) that is formed thereon as required. However, in orderto simplify the figures herein, it is shown as a plane substrate.

FIG. 1 is a cross-sectional view illustrating an electronic device 100in accordance with some embodiments of the present disclosure. It shouldbe noted that the electronic device 100 may include a display device, anantenna device, a sensing device or a tiled device, but is not limitedthereto. The electronic device may be a bendable or flexible electronicdevice. The electronic device may include, for example, a liquid-crystallight-emitting diode, and the light-emitting diode may include, forexample, an organic light-emitting diode (OLED), a mini LED, a micro LEDor quantum dot (QD) light-emitting diode (which may be referred to asQLED, QDLED), fluorescence, phosphor, or other suitable materials, andthe materials can be arranged and combined arbitrarily, but the presentdisclosure is not limited thereto. The antenna device may be, forexample, a liquid-crystal antenna, but it is not limited thereto. Thetiled device may be, for example, a display tiled device or an antennatiled device, but it is not limited thereto. It should be noted that theelectronic device 100 may be any of the aforementioned arrangement butis not limited thereto.

As shown in FIG. 1, the electronic device 100 includes a substrate 110and a plurality of light-emitting elements (including a firstlight-emitting element 120, a second light-emitting element 130 and athird light-emitting element 140) that are disposed on the substrate110. It should be understood that although three light-emitting elementsare shown in this embodiment, those skilled in the art may arbitrarilyadjust the number of light-emitting elements as required. In thisembodiment, the substrate may supply the same current to the firstlight-emitting element 120, the second light-emitting element 130, andthe third light-emitting element 140, the first light-emitting element120, the second light-emitting element 130 and the third light-emittingelement 140 emit colored light. For example, the first light-emittingelement 120, the second light-emitting element 130 and the thirdlight-emitting element 140 each include a blue LED. A light-transmittinglayer 124 is disposed on the first light-emitting element 120, a colorconversion layer 134 is disposed on the second light-emitting element130, and a color conversion layer 144 is disposed on the thirdlight-emitting element 140, the first light-emitting element 120, thesecond light-emitting element 130 and the third light-emitting element140 emit different colors of light. In other embodiments, the firstlight-emitting element 120 includes a blue LED, the secondlight-emitting element 130 includes a green LED, and the thirdlight-emitting element 140 includes a red LED. In other embodiments, atleast one of the first light-emitting element 120, the secondlight-emitting element 130 and the third light-emitting element 140includes an ultraviolet light-emitting diode (UV LED), but the presentdisclosure is not limited thereto.

Referring to FIG. 1, the first light-emitting element 120 includes asemiconductor layer 121, a light-emitting layer 122, a semiconductorlayer 123, and a light-transmitting layer 124. In this embodiment, thesemiconductor layer 121 and the semiconductor layer 123 may includegallium nitride (GaN) or any other suitable semiconductor materials, butthey are not limited thereto. In some embodiments, the semiconductorlayer 121 and the semiconductor layer 123 may include different types ofsemiconductor materials. For example, the semiconductor layer 121 may bea p-type semiconductor layer, the semiconductor layer 123 may be ann-type semiconductor layer, but they are not limited thereto. Thelight-emitting layer 122 is disposed between the semiconductor layer 121and the semiconductor layer 123. The light-emitting layer 122 mayinclude, a homojunction, a heterojunction, a single-quantum well (SQW),a multiple-quantum well (MQW), any other suitable structure or acombination thereof, but it is not limited thereto. The light-emittinglayer 122 may emit blue light, but it is not limited thereto. In thisembodiment, the light-transmitting layer 124 is disposed on thesemiconductor layer 123, the light emitted by the light-emitting layer122 may be irradiated to the outside through the light-transmittinglayer 124.

The semiconductor layer 121 may be connected to and/or electricallyconnected to the substrate 110 through an ohmic contact electrode 161and a conductive pad 151. In this embodiment, the conductive pad 151 andthe semiconductor layer 121 may completely cover the ohmic contactelectrode 161. In other words, the conductive pad 151 may be in contactwith the semiconductor layer 121, and the first light-emitting element120 may be disposed on the substrate 110 more stably. For example, theohmic contact electrode 161 may include indium tin oxide (ITO), silver(Ag), nickel (Ni), gold (Au), platinum (Pt), gold beryllium alloy(AuBe), gold germanium Alloy (AuGe), chromium (Cr) or any other suitableconductive material.

In addition, the second light-emitting element 130 may have a structuresimilar to the first light-emitting element 120. For example, the secondlight-emitting element 130 includes a semiconductor layer 131, alight-emitting layer 132, a semiconductor layer 133, and a colorconversion layer 134. In this embodiment, the light-emitting layer 132disposed between the semiconductor layer 131 and the semiconductor layer133 emits blue light, the color conversion layer 134 is disposed on thesemiconductor layer 133 to convert the blue light into green light orred light. Similarly, the semiconductor layer 131 may be connected toand/or electrically connected to the substrate 110 through an ohmiccontact electrode 162 and a conductive pad 152. The third light-emittingelement 140 may have a structure similar to the second light-emittingelement 130. For example, the third light-emitting element 140 includesa semiconductor layer 141, a light-emitting layer 142, a semiconductorlayer 143 and/or a color conversion layer 144. In this embodiment, thecolor conversion layer 144 may convert blue light into the other ofgreen light or red light (which is different from the light converted bythe color conversion layer 134). Similarly, the semiconductor layer 141may be connected to and/or electrically connected to the substrate 110through an ohmic contact electrode 163 and a conductive pad 153.

In addition, in this embodiment, the semiconductor layer 123, thesemiconductor layer 133 and the semiconductor layer 143 may be connectedto and/or electrically connected to the substrate 110 through an ohmiccontact electrode 180 and a conductive pad 170. In some embodiments, thedimensions of the ohmic contact electrode 180 and the conductive pad 170in the horizontal direction (the X-Y plane) are substantially the same,but they are not limited thereto. In other embodiments, the dimensionsof the ohmic contact electrode 180 and the conductive pad 170 in thehorizontal direction may be different from each other. In addition, insome embodiments, the ohmic contact electrode 180 may be omitted. Thatis, the conductive pad 170 may be in direct contact with thesemiconductor layer 123, the semiconductor layer 133 and thesemiconductor layer 143.

FIG. 2 is a top view illustrating the electronic device 100 shown inFIG. 1. When the substrate 110 supplies the same amount of current tothe first light-emitting element 120, the second light-emitting element130 and the third light-emitting element 140, the contact area (which islocated on the X-Y plane) of the semiconductor layer and the ohmiccontact electrode can affect the current density supplied to thelight-emitting element. The contact area between the semiconductor layerand the ohmic contact electrode has a negative correlation with thecurrent density of the light-emitting element. In other words, thelarger the contact area between the semiconductor layer and the ohmiccontact electrode, the lower the current density of the light-emittingelement. In general, the light-emitting elements with higherlight-emitting efficiency needs to a lower current density (that is, thearea where the ohmic contact electrode is in contact with thesemiconductor layer needs to be increased), but it is not limitedthereto. The relationship between the light-emitting efficiency of thelight-emitting element and the current density will be described in moredetail below in accompany with FIG. 12.

For example, in this embodiment, the light-emitting efficiency of thefirst light-emitting element 120 is greater than the light-emittingefficiency of the second light-emitting element 130, the light-emittingefficiency of the second light-emitting element 130 is greater than thelight-emitting efficiency of the third light-emitting element 140.Therefore, the area of the ohmic contact electrode 161 connected to thefirst light-emitting element 120 on the X-Y plane (contact with thesemiconductor layer 121) is larger than the area of the ohmic contactelectrode 162 connected to the second light-emitting element 130 on theX-Y plane (contact with the semiconductor layer 131), and is even largerthan the area of the ohmic contact electrode 163 that is connected tothe third light-emitting element 140 on the X-Y plane (contact with thesemiconductor layer 141). As such, the ratio of the area of the ohmiccontact electrode 161 to the area of the semiconductor layer 121 isdifferent from the ratio of the area of the ohmic contact electrode 162to the area of the semiconductor layer 131 and the ratio of the area ofthe ohmic contact electrode 163 to the area of the semiconductor layer141. For example, the ratio of the area of the ohmic contact electrode161 to the area of the semiconductor layer 121 is greater than the ratioof the area of the ohmic contact electrode 162 to the area of thesemiconductor layer 131, which is even greater than the ratio of thearea of the ohmic contact electrode 163 to the area of the semiconductorlayer 141, but it is not limited thereto.

It should be understood that the above relationship between thelight-emitting efficiency of the light-emitting element merely serves asan example. In fact, all the light-emitting elements described in thepresent disclosure may have different light-emitting efficiency fromeach other, and the aforementioned light-emitting efficiency may havearbitrary combination of magnitude relationships. For example, in someembodiments, the light-emitting efficiency of the first light-emittingelement is less than the light-emitting efficiency of the secondlight-emitting element, and the light-emitting efficiency of the secondlight-emitting element is less than the light-emitting efficiency of thethird light-emitting element. Those skilled in the art may adjust thearea of the ohmic contact electrode in response to differentcombinations of magnitude relationships of light-emitting efficiencybased on the embodiments of the present disclosure. Unless definedotherwise, in the following embodiments, the light-emitting efficiencyof the first light-emitting element is greater than the light-emittingefficiency of the second light-emitting element, which is furthergreater than the light-emitting efficiency of the third light-emittingelement, and it will not be repeated again.

FIG. 3 is a cross-sectional view illustrating the electronic device 200in accordance with some embodiments of the present disclosure, and FIG.4 is a top view illustrating the electronic device 200 shown in FIG. 3.It should be noted that the electronic device 200 may include the sameor similar parts as the electronic device 100 shown in FIGS. 1 and 2,and the aforementioned same or similar parts will be labeled withsimilar numerals. These parts will not be repeated again. For example,the electronic device 200 includes a substrate 210 and a firstlight-emitting element 220, a second light-emitting element 230, and athird light-emitting element 240 that are disposed on the substrate 210.Semiconductor layers 221, 231, and 241 of the light-emitting elementsare connected to the substrate 210 via ohmic contact electrodes 261,262, 263 and conductive pads 251, 252, 253.

The ohmic contact electrode 262 and the ohmic contact electrode 263 ofthe electronic device 200 in this embodiment may be divided into aplurality of separate portions. It should be understood that, in thisembodiment, the area where the ohmic contact electrode 262 contacts thesemiconductor layer 231 is a sum of the areas of all the portions of theohmic contact electrode 262 on the X-Y plane. Similarly, the area wherethe ohmic contact electrode 263 contacts the semiconductor layer 241 isa sum of the areas of all the portions of the ohmic contact electrode263 on the X-Y plane. By designing the ohmic contact electrode 262 andthe ohmic contact electrode 263 into a plurality of separate parts,which can increase a flexibility or diversity in design and/ormanufacturing.

FIG. 5 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure. It should benoted that the electronic device 300 in this embodiment may include thesame or similar parts as the electronic device 100 shown in FIG. 1 andFIG. 2, and the aforementioned same or similar parts will be labeled assimilar numerals. These parts will not be described in detail again. Forexample, the electronic device 300 includes a substrate 310 and a firstlight-emitting element 320, a second light-emitting element 330 and athird light-emitting element 340 that are disposed on the substrate 310.Semiconductor layers 321, 331 and 341 of the light-emitting elements areconnected to the substrate 310 via ohmic contact electrodes 361, 362,363 and conductive pads 351, 352, 353.

The conductive pad 351, the conductive pad 352 and/or the conductive pad353 of the electronic device 300 in this embodiment are not completelycovered by the ohmic contact electrode 361, the ohmic contact electrode362 and/or the ohmic contact electrode 363, respectively. When viewedalong a side direction (e.g. the X direction and/or the Y direction),the ohmic contact electrode 361, the ohmic contact electrode 362 and/orthe ohmic contact electrode 363 are exposed from the conductive pad 351,the conductive pad 352 and the conductive pad 353, respectively. In thisembodiment, the light-emitting efficiency of the third light-emittingelement 340 is greater than the light-emitting efficiency of the secondlight-emitting element 330, the light-emitting efficiency of the secondlight-emitting element 330 is greater than the light-emitting efficiencyof the first light-emitting element 320. Therefore, the area of theohmic contact electrode 363 connected to the third light-emittingelement 340 on the X-Y plane (contact with the semiconductor layer 341)is larger than the area of the ohmic contact electrode 362 connected tothe second light-emitting element 330 on the X-Y plane (contact with thesemiconductor layer 331), and the area of the ohmic contact electrode363 connected to the third light-emitting element 340 on the X-Y planeis even larger than the area of the ohmic contact electrode 361connected to the first light-emitting element 320 on the X-Y plane(contact with the semiconductor layer 321).

In addition, in this embodiment, the area of the conductive pad 351 onthe X-Y plane is larger than the area of the ohmic contact electrode 361on the X-Y plane. The area of the conductive pad 352 on the X-Y plane issubstantially equal to the area of the ohmic contact electrode 362 onthe X-Y plane. The area of the conductive pad 353 on the X-Y plane issmaller than the area of the ohmic contact electrode 363 on the X-Yplane. The present disclosure is not limited thereto. Those skilled inthe art may arbitrarily adjust the area relationship between theconductive pad 351 and the ohmic contact electrode 361, between theconductive pad 352 and the ohmic contact electrode 362, or between theconductive pad 353 and the ohmic contact electrode 363 as required.Similarly, the area relationship between the conductive pad and theohmic contact electrode described above may also adopt any combinationof the conductive pad and the ohmic contact electrode described in thepresent disclosure, and it will not be described in detail below.

FIG. 6 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure. It should benoted that the electronic device 400 in this embodiment may include thesame or similar parts as the electronic device 100 shown in FIGS. 1 and2, and the aforementioned same or similar parts will be labeled withsimilar numerals. These parts will not be described in detail again. Forexample, the electronic device 400 includes a substrate 410 and a firstlight-emitting element 420, a second light-emitting element 430 and athird light-emitting element 440 that are disposed on the substrate 410.Semiconductor layers 421, 431 and 441 of the light-emitting elements areeach connected to the substrate 410 via ohmic contact electrodes 461,462, 463 and/or conductive pads 451, 452, 453. In addition,Semiconductor layers 423, 433, and 443 of the light-emitting elementsare connected to the substrate 410 via ohmic contact electrodes 481,482, 483 and/or conductive pads 471, 472, 473, respectively.

The first light-emitting element 420 of the electronic device 400 inthis embodiment includes an ultraviolet LED, and a color conversionlayer 424 can be disposed on the semiconductor layer 423 of the firstlight-emitting element 420. The light emitted by the light-emittinglayer 422 is converted into blue light and irradiated to the outside.Similarly, the second light-emitting element 430 and the thirdlight-emitting element 440 may include ultraviolet LEDs, and the secondlight-emitting element 430 and the third light-emitting element 440 areprovided with a color conversion layer 434 and a color conversion layer444, respectively. The light emitted from the light-emitting layer 432and the light-emitting layer 442 is converted into green light or redlight and irradiated to the outside. In addition, in this embodiment,the sizes of the ohmic contact electrode 481, the ohmic contactelectrode 482 and the ohmic contact electrode 483 on the X-Y plane arenot uniform. As shown in FIG. 6, the ohmic contact electrode 481, theohmic contact electrode 482 and the ohmic contact electrode 483 may havean area relationship similar to that of the ohmic contact electrode 461,the ohmic contact electrode 462 and the ohmic contact electrode 463.That is, on the X-Y plane, the area of the ohmic contact electrode 481is larger than the area of the ohmic contact electrode 482, the area ofthe ohmic contact electrode 482 is larger than the area of the ohmiccontact electrode 483, but the present disclosure is not limitedthereto.

FIG. 7 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure. It should benoted that the electronic device 500 in this embodiment may include thesame or similar parts as the electronic device 100 shown in FIG. 1 andFIG. 2. The same or similar parts will be denoted by similar numerals,and will not be described in detail again. For example, the electronicdevice 500 includes a substrate 510 and a first light-emitting element520, a second light-emitting element 530 and a third light-emittingelement 540 that are disposed on the substrate 510. Semiconductor layers521, 531 and 541 of the light-emitting elements are each connected tothe substrate 510 via ohmic contact electrodes 561, 562, 563 andconductive pads 551, 552, 553.

In this embodiment, the first light-emitting element 520 of theelectronic device 500 includes a blue LED, the second light-emittingelement 530 includes a green LED, and the third light-emitting element540 includes a red LED. For example, the semiconductor layer 531 and thesemiconductor layer 533 of the second light-emitting element 530 includegallium nitride or any other suitable semiconductor material, but theyare not limited thereto. The semiconductor layer 541 and thesemiconductor layer 543 of the third light-emitting element 540 includealuminum gallium indium phosphide (AlGaInP) or any other suitablesemiconductor material, but they are not limited thereto. Since theabove light-emitting elements may directly emit blue, green or redlight, it is not necessary to provide a light-transmitting layer and/ora color conversion layer in this embodiment, and thereby simplifying themanufacturing process of the electronic device 500.

FIG. 8 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure. It should benoted that the electronic device 600 may include the same or similarparts as the electronic device 100 shown in FIG. 1 and FIG. 2. The sameor similar parts will be labeled with similar numerals, and will not bedescribed in detail again. For example, the electronic device 600includes a substrate 611 and a first light-emitting element 620, asecond light-emitting element 630, a third light-emitting element 640that are disposed on the substrate 611. The first light-emitting element620, the second light-emitting element 630 and the third light-emittingelement 640 of the electronic device 600 in this embodiment may becovered by the protective layer 651 to reduce the chance that thelight-emitting elements are damaged due to external force.

In addition, the electronic device 600 further includes a substrate 612disposed opposite to the substrate 611. On the substrate 612, alight-transmitting layer 661 is disposed corresponding to the firstlight-emitting element 620, a color conversion layer 662 is disposedcorresponding to the second light-emitting element 630, and a colorconversion layer 663 is disposed corresponding to the thirdlight-emitting element 640. In this embodiment, a light-shielding layer670 is disposed between the light-transmitting layer 661 and the colorconversion layer 662, and between the color conversion layer 662 and thecolor conversion layer 663 to reduce the mixing of light from differentlight-emitting units with each other, which may affect the performanceof the electronic device 600. A protective layer 653 is disposed underthe light-transmitting layer 661, the color conversion layer 662, thecolor conversion layer 663 and the light-shielding layer 670 forreducing the damage of the layers due to external forces. The protectivelayer 651 and the protective layer 653 may be bonded via the adhesivelayer 652, and therefore bonding the substrate 612 to the substrate 611.

FIG. 9 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure. It should benoted that the electronic device 700 in this embodiment may include thesame or similar parts as the electronic device 600 shown in FIG. 6, andthe aforementioned same or similar parts will be labeled with similarnumerals and will not be described in detail again. For example, theelectronic device 700 includes a substrate 711 and a substrate 712 thatare opposite to each other. A first light-emitting element 720, a secondlight-emitting element 730 and a third light-emitting element 740 aredisposed on the substrate 711. A color conversion layer 761, a colorconversion layer 762, a color conversion layer 763 and a light shieldinglayer 770 are disposed on the substrate 712.

In this embodiment, the first light-emitting element 720 of theelectronic device 700 includes an ultraviolet LED. Therefore, acorresponding color conversion layer 761 can be disposed on the firstlight-emitting element 720, the light emitted by the firstlight-emitting element 720 is converted into blue light and irradiatedto the outside. Similarly, the second light-emitting element 730 and thethird light-emitting element 740 may include ultraviolet LEDs, thesecond light-emitting element 730 and the third light-emitting element740 may be provided with corresponding color conversion layers 762 and763 to convert the emitted light to green light or red light. It shouldbe understood that, for the sake of brevity, the size relationshipbetween different ohmic contact electrodes is not specifically describedin the embodiments shown in FIG. 8 and FIG. 9, but those skilled in theart may appropriately arrange the ohmic contact electrodes based onother embodiments in the present disclosure.

FIG. 10 is a cross-sectional view illustrating the electronic device inaccordance with some embodiments of the present disclosure. It should benoted that the electronic device 800 in this embodiment may include thesame or similar parts as the electronic device 100 shown in FIGS. 1 and2. The aforementioned same or similar parts will be labeled with similarnumerals and will not be described in detail again. For example, theelectronic device 800 includes a substrate 811 and a firstlight-emitting element 820, a second light-emitting element 830, a thirdlight-emitting element 840 that are disposed on the substrate 811, andthe foregoing light-emitting elements are each connected to thesubstrate 811 via ohmic contact electrodes 861, 862, 863 and conductivepads 851, 852, 853.

The electronic device 800 in this embodiment further includes asubstrate 812, disposed opposite to the substrate 811. In the presentembodiment, the first light-emitting element 820, the secondlight-emitting element 830 and the third light-emitting element 840 areconnected to the substrate 812 via conductive pads 870. The substrate812 may protect the first light-emitting element 820, the secondlight-emitting element 830 and the third light-emitting element 840.

FIG. 11 is a cross-sectional view illustrating a conductive pad 880 inaccordance with some embodiments of the present disclosure. As shown inFIG. 11, the conductive pad 880 includes a bonding layer 881, a barrierlayer 882 and an adhesive layer 883 sequentially stacked. In someembodiments, the bonding layer 881 is disposed on the substrate. Thebarrier layer 882 is disposed on the bonding layer 881. The adhesivelayer 883 is disposed on the barrier layer 882 and is in contact withthe ohmic contact electrode. For example, the bonding layer 881 mayinclude copper (Cu), gold (Au), silver (Ag), tin (Sn), indium (In),other suitable metal materials or a combination thereof, but it is notlimited thereto. The barrier layer 882 may include nickel (Ni), platinum(Pt), other suitable metal materials or a combination thereof, but it isnot limited thereto. The adhesive layer 883 may include chromium (Cr),titanium (Ti), other suitable metal materials or a combination thereof,but it is not limited thereto. It should be understood that theconductive pad 880 in this embodiment can be applied to the conductivepads in all the above embodiments, but it is not limited thereto.

FIG. 12 is a schematic diagram illustrating the relationship between thelight-emitting efficiency and the current density in accordance withsome other embodiments of the present disclosure. As shown in FIG. 12, Agraph 900 shows lines 901, 902 and 903. The line 901 may include bluelight, the line 902 may include green light, the line 903 may includered light, but they are not limited thereto. The lines 901, 902 and 903each indicate the relationship between the light-emitting efficiency andthe current density of different light-emitting elements. The verticalaxis of the graph 900 indicates the light-emitting efficiency (%), andthe horizontal axis indicates the current density (A/cm²). In order tomake the light-emitting efficiency of each light-emitting elementuniform, the current density required for each light-emitting element toreach the target light-emitting efficiency can be obtained from graph900. Then, the size of the ohmic contact electrode may be adjustedaccording to the current density value shown in the graph 900. It shouldbe understood that the relationship between the light-emittingefficiency and the current density shown in the graph 900 merely servesas an example. The present disclosure is not limited thereto. In otherembodiments, the relationship between the light-emitting efficiency andthe current density of the light-emitting element may be different fromthe relationship shown by the lines 901, 902 and 903.

As set forth above, some embodiments of the present disclosure providean electronic device having ohmic contact electrodes with differentsizes. The sizes of the ohmic contact electrodes may be adjusted, suchthat the light-emitting efficiencies of the light-emitting elements tendto be uniform. As a result, white color balance may be achieved withoutthe complicated manufacturing process for the light-emitting elements.

While the embodiments and the advantages of the present disclosure havebeen described above, it should be understood that those skilled in theart may make various changes, substitutions, and alterations to thepresent disclosure without departing from the spirit and scope of thepresent disclosure. It should be noted that different embodiments in thepresent disclosure may be arbitrarily combined as other embodiments aslong as the combination conforms to the spirit of the presentdisclosure. In addition, the scope of the present disclosure is notlimited to the processes, machines, manufacture, composition, devices,methods and steps in the specific embodiments described in thespecification. Those skilled in the art may understand existing ordeveloping processes, machines, manufacture, compositions, devices,methods and steps from some embodiments of the present disclosure.Therefore, the scope of the present disclosure includes theaforementioned processes, machines, manufacture, composition, devices,methods, and steps. Furthermore, each of the appended claims constructsan individual embodiment, and the scope of the present disclosure alsoincludes every combination of the appended claims and embodiments.

What is claimed is:
 1. An electronic device, comprising: a substrate; afirst light-emitting element disposed on the substrate and configured toemit a first color light under a first current density when thesubstrate provides a first current to the first light-emitting element;and a second light-emitting element disposed on the substrate andconfigured to emit a second color light under a second current densitywhen the substrate provides a second current to the secondlight-emitting element, wherein the first current is equal to the secondcurrent, and the first current density is different from the secondcurrent density.
 2. The electronic device as claimed in claim 1, whereinthe first light-emitting element comprises a first ohmic contactelectrode, and the first current density is defined by a ratio of thefirst current and an area of the first ohmic contact electrode.
 3. Theelectronic device as claimed in claim 2, wherein the secondlight-emitting element comprises a second ohmic contact electrode, andthe second current density is defined by a ratio of the second currentand an area of the second ohmic contact electrode.
 4. The electronicdevice as claimed in claim 3, wherein the area of the first ohmiccontact electrode is different from the area of the second ohmic contactelectrode.
 5. The electronic device as claimed in claim 1, wherein thefirst color light is a blue light, the second color light is a greenlight or a red light, and the first current density is less than thesecond current density.
 6. The electronic device as claimed in claim 1,further comprising a third light-emitting element disposed on thesubstrate and configured to emit a third color light under a thirdcurrent density when the substrate provides a third current to the thirdlight-emitting element, wherein the third current is equal to the firstcurrent, and the third current density is different from the firstcurrent density and the second current density.
 7. The electronic deviceas claimed in claim 6, wherein the third light-emitting elementcomprises a third ohmic contact electrode, and the third current densityis defined by a ratio of the third current and an area of the thirdohmic contact electrode.
 8. The electronic device as claimed in claim 7,wherein the area of the first ohmic contact electrode is different fromthe area of the third ohmic contact electrode.
 9. An electronic device,comprising: a substrate; a first light-emitting element disposed on thesubstrate and configured to emit a first color light, wherein the firstlight-emitting element comprises a first semiconductor layer and a firstohmic contact electrode in contact with the first semiconductor layer;and a second light-emitting element disposed on the substrate andconfigured to emit a second color light, wherein the secondlight-emitting element comprises a second semiconductor layer and asecond ohmic contact electrode in contact with the second semiconductorlayer, wherein a first ratio of an area of the first ohmic contactelectrode and an area of the first semiconductor layer is different froma second ratio of an area of the second ohmic contact electrode and anarea of the second semiconductor layer.
 10. The electronic device asclaimed in claim 9, wherein the area of the first semiconductor layer isthe same as the area of the second semiconductor layer.
 11. Theelectronic device as claimed in claim 9, wherein the first semiconductorlayer and the second semiconductor layer are semiconductor layers of thesame type.
 12. The electronic device as claimed in claim 11, wherein thearea of the first semiconductor layer is the same as the area of thesecond semiconductor layer.
 13. The electronic device as claimed inclaim 9, wherein the second light-emitting element further comprises acolor conversion layer located on the second semiconductor layer. 14.The electronic device as claimed in claim 9, wherein the first colorlight is a blue light, the second color light is a green light or a redlight, and the first ratio is higher than the second ratio.
 15. Theelectronic device as claimed in claim 9, wherein the firstlight-emitting element further comprises a bonding pad electricallyconnected to the first ohmic contact electrode and the substrate. 16.The electronic device as claimed in claim 9, further comprising a thirdlight-emitting element disposed on the substrate and configured to emita third color light, wherein the third light-emitting element comprisesa third semiconductor layer and a third ohmic contact electrode incontact with the third semiconductor layer, and a third ratio of an areaof the third ohmic contact electrode and an area of the thirdsemiconductor layer is different from the first ratio and the secondratio.
 17. The electronic device as claimed in claim 16, wherein thearea of the first semiconductor layer is the same as the area of thethird semiconductor layer.
 18. The electronic device as claimed in claim16, wherein the first semiconductor layer and the third semiconductorlayer are semiconductor layers of the same type.
 19. The electronicdevice as claimed in claim 16, wherein the first color light is a bluelight, the third color light is a green light or a red light, and thefirst ratio is greater than the third ratio.
 20. The electronic deviceas claimed in claim 9, wherein the first ohmic contact electrode or thesecond ohmic contact electrode is divided into a plurality of separate